Various surgical cutting blade systems exist that involve an electrically heated blade. Some of these cutting blade systems have a ceramic component with a metalized layer thereon. Examples are found in U.S. Pat. Nos. 3,768,482; 4,161,950; 4,850,353; 4,862,890; 4,958,539; and 5,925,039. In addition, various scissor-type cutting systems exist that involve a ceramic component and a metalized component. Examples are found in U.S. Pat. Nos. 5,352,222; 5,893,846; and 6,447,511. Unfortunately, the above systems all involve cutting tissue, and are not adapted to tissue sealing.
U.S. Pat. No. 5,456,684 describes a multifunction surgical device that can be used for cutting or cauterizing tissue, providing irrigation or for electrosurgery. Unfortunately, this device can not be used for both cutting and sealing tissue at the same time. Moreover, this device passes current through the tissue to provide cauterization.
U.S. Pat. Nos. 6,235,027 and 6,533,778 and U.S. Published Application Nos. 2001/0014803 and 2003/0125735 to Herzon all describe a thermal cautery forceps system. This system uses a pair of ceramic heaters having opposing flattened surfaces. These opposing flattened surfaces are brought together to pinch tissue therebetween. The ceramic heaters heat and squeeze the tissue to cauterize it. Specifically, Herzon describes a ceramic heater in which the ceramic is a semiconductor ceramic. (Being resistive, it generates heat when electrical current is passed through it). This semiconductor ceramic member has homogeneous resistivity, and thus it generates heat uniformly across its surface. Because heating is uniform, there is only a sealing zone created if heated to sealing temperatures and only a cutting zone created if heated to cutting temperatures. As a result, the Herzon system can only be used to cauterize tissue, or to cut through tissue, but not both at the same time.